Amazon.com: Teyleten Robot Nano IO Expansion Shield Sensor Module for Arduino UNO R3 Nano 3pcs : Electronics
Amazon.com: CQRobot Ocean: MCP23017 IO Expansion Board Compatible with Raspberry Pi/Micro:bit/Arduino/STM32 Motherboard. I2C Interface, Expands 16 I/O Pins, Up to 8 Expansion Boards Can be Used Simultaneously. : Electronics
Amazon.com: ALMOCN 10pcs PCF8574 IO Expansion Board I/O Expander I2C-Bus Evaluation Development Module for Arduino Raspberry Pi : Electronics
Arduino Based Amazon Echo Using 1Sheeld - Hackster.io
Amazon.com: 3PCS Mini MP3 Player Audio Module MP3 Voice Decode Board TF Card U Disk IO/Serial Port/AD Board DFPlayer Audio Voice Music Module for Arduino : Electronics
Amazon.com: Velleman VMA05 I/O Shield for Arduino, 1 Grade to 12 Grade, 2.75" L x 2.16" W x 1.18" H : Electronics
Amazon.com: Treedix Proto Screw Shield V2 Expansion Board Breakout Board IO Sensor Module Terminal Block Compatible with Arduino UNO R3 with Cable : Electronics
Amazon.com: Arduino UNO REV3 [A000066] : Electronics
Amazon.com: ACEIRMC 3pcs PCF8575 IO Expander Board Module I2C to 16IO IIC I2C I/O Extension Shield Module 16 bit SMBus I/O Ports for Arduino R3 (3pcs) : Electronics